Making and using hot mixed lime mortars

This one day workshop aims to provide an introductory guide
to the preparation and use of ‘hot mixed’ lime mortars, that is, mortars
prepared by slaking quicklime, sand and natural hydraulic lime binders (and
possibly other additives like tallow or pozzolans) to more closely mimic the
appearance and technical performance of conservation mortars and in some cases
offer advantages in use and technical performance over more conventional ‘cold
mortars’. More and more clients and specifiers are asking building contractors
to make and use ‘hot mixed’ mortars on their repair jobs, so get ahead of the
game and brush up your knowledge and skills with us.

‘Hot mixed’ mortars have a long history of use in the UK,
with evidence visible throughout the nation on traditional buildings and
structures. Since the lime revival of the mid 1990s however, the preparation
and use of conservation mortars has been largely dominated by lime putty bound
mortars or ‘cold’ mortars based on natural hydraulic limes (NHLs). Whilst all
these mortar types have their place, a renewed interest in the production of what
are perceived to be more authentic mortar preparations using quicklime and sand
has been growing and this workshop aims to take the building contractor through
the process of making and using ‘hot mixed’ mortars safely, constituents to be
used, preparation of mortars, correct mixing equipment and critically at which
point these mortars should be used for particular applications.

By the end of the course, attendees will be able to
recognise traditionally made ‘hot mixed’ mortars in historic structures and
buildings and be able to develop the skills to produce and successfully cure ‘hot
mixed’ mortars in relation to authenticity, performance, exposure, season,
substrate and nature of the masonry repairs required.

Course suitability

This course is aimed at building contractors (including
stonemasons, bricklayers, lime workers and labourers) involved in historic
building repair, reconstruction and the consolidation of historic structures
and give you the confidence to make and use ‘hot mixed’ mortars successfully.

Learning outcomes:

Ability to recognise traditionally made ‘hot mixed’ mortars
in historic buildings and structures;

Ability to make and use ‘hot mixed’ mortars successfully;

Understand at which point, post production of ‘hot mixed’
mortars, these mortars should be used.

Course Programme – through a blend of theory and practical
sessions

Health and safety briefing;

Historic preparation and use of lime (and other) based
mortars;

Understanding the range and production methods of lime
binders available in the UK today;

Understanding other mortar constituents including sands and
aggregates, pozzolans and other additives such as animal fats and milk
products;

Making and using hot mixed lime mortars for repairs to
traditional buildings– factors to consider, mix proportions, appropriate mixing
equipment, when to use ‘hot mixed’ mortars post production and Building
Standards;

Perceived barriers to specification – including Health and
Safety for safe storage of materials, mixing regimes and safety in use.